Touch screens have become the dominant human-computer interaction means of personal mobile communication devices and integrated information terminals such as tablets, smartphones, and super laptops, due to their advantages such as ease of use, intuitiveness and flexibility. Touch screens can be divided into four main types of resistive touch screens, capacitive touch screens, infrared touch screens and surface wave (SAW) touch screens according to a touch control principle. Among them, the capacitive touch screens have now become the main application of touch interaction of small or medium size information terminals, because the capacitive touch screens have multi-touch function, short reaction time, long service life, high transmittance and superior user experience, and as the processes gradually become mature, yield rate has been significantly improved, making the price of capacitive screens lower and lower.